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Java > Open Source Codes > com > jcraft > jzlib > ZInputStream


1 /* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
2 /*
3 Copyright (c) 2001 Lapo Luchini.
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are met:
7
8   1. Redistributions of source code must retain the above copyright notice,
9      this list of conditions and the following disclaimer.
10
11   2. Redistributions in binary form must reproduce the above copyright
12      notice, this list of conditions and the following disclaimer in
13      the documentation and/or other materials provided with the distribution.
14
15   3. The names of the authors may not be used to endorse or promote products
16      derived from this software without specific prior written permission.
17
18 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
19 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS
21 OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
22 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
24 OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
25 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
26 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
27 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 /*
30  * This program is based on zlib-1.1.3, so all credit should go authors
31  * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
32  * and contributors of zlib.
33  */
34
35 package com.jcraft.jzlib;
36 import java.io.*;
37
38 public class ZInputStream extends FilterInputStream {
39
40   protected ZStream z=new ZStream();
41   protected int bufsize=512;
42   protected int flush=JZlib.Z_NO_FLUSH;
43   protected byte[] buf=new byte[bufsize],
44                    buf1=new byte[1];
45   protected boolean compress;
46
47   protected InputStream in=null;
48
49   public ZInputStream(InputStream in) {
50     this(in, false);
51   }
52   public ZInputStream(InputStream in, boolean nowrap) {
53     super(in);
54     this.in=in;
55     z.inflateInit(nowrap);
56     compress=false;
57     z.next_in=buf;
58     z.next_in_index=0;
59     z.avail_in=0;
60   }
61
62   public ZInputStream(InputStream in, int level) {
63     super(in);
64     this.in=in;
65     z.deflateInit(level);
66     compress=true;
67     z.next_in=buf;
68     z.next_in_index=0;
69     z.avail_in=0;
70   }
71
72   /*public int available() throws IOException {
73     return inf.finished() ? 0 : 1;
74   }*/
75
76   public int read() throws IOException {
77     if(read(buf1, 0, 1)==-1)
78       return(-1);
79     return(buf1[0]&0xFF);
80   }
81
82   private boolean nomoreinput=false;
83
84   public int read(byte[] b, int off, int len) throws IOException {
85     if(len==0)
86       return(0);
87     int err;
88     z.next_out=b;
89     z.next_out_index=off;
90     z.avail_out=len;
91     do {
92       if((z.avail_in==0)&&(!nomoreinput)) { // if buffer is empty and more input is avaiable, refill it
93 z.next_in_index=0;
94     z.avail_in=in.read(buf, 0, bufsize);//(bufsize<z.avail_out ? bufsize : z.avail_out));
95 if(z.avail_in==-1) {
96       z.avail_in=0;
97       nomoreinput=true;
98     }
99       }
100       if(compress)
101     err=z.deflate(flush);
102       else
103     err=z.inflate(flush);
104       if(nomoreinput&&(err==JZlib.Z_BUF_ERROR))
105         return(-1);
106       if(err!=JZlib.Z_OK && err!=JZlib.Z_STREAM_END)
107     throw new ZStreamException((compress ? "de" : "in")+"flating: "+z.msg);
108       if((nomoreinput||err==JZlib.Z_STREAM_END)&&(z.avail_out==len))
109     return(-1);
110     }
111     while(z.avail_out==len&&err==JZlib.Z_OK);
112     //System.err.print("("+(len-z.avail_out)+")");
113 return(len-z.avail_out);
114   }
115
116   public long skip(long n) throws IOException {
117     int len=512;
118     if(n<len)
119       len=(int)n;
120     byte[] tmp=new byte[len];
121     return((long)read(tmp));
122   }
123
124   public int getFlushMode() {
125     return(flush);
126   }
127
128   public void setFlushMode(int flush) {
129     this.flush=flush;
130   }
131
132   /**
133    * Returns the total number of bytes input so far.
134    */
135   public long getTotalIn() {
136     return z.total_in;
137   }
138
139   /**
140    * Returns the total number of bytes output so far.
141    */
142   public long getTotalOut() {
143     return z.total_out;
144   }
145
146   public void close() throws IOException{
147     in.close();
148   }
149 }
150
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